I think one needs to understand PG's bias.
He has written excellent technical books that are both deep and a pleasure to read.
He is not in the business of writing the next War and Peace.
Good writers can use big words well. Someone who has been writing for 20 years is able to reach for a precise word in the right situation, to get the right effect. 99% of the people are not good writers, and when they try to do that, it comes across unreadable in the best case and self-important in the average case.
Just say what you mean. Text is beautiful because it flows, the sentence might evoke the thing it's describing by its sounds or rhythm or structure. It's not beautiful because it uses big words.
It could also be about appreciating subtler aspects of life as I grow older. Regardless, the net result is my impressions about "write simply" suggestions are exactly what you stated.